Combined solid adsorption-hydrotreating process for whole crude oil desulfurization

ABSTRACT

A whole crude oil desulfurization system and process includes a combination of an adsorption zone and a hydroprocessing zone. This combined process and system reduces the requisite throughput for the hydroprocessing unit, conventionally a very costly and process both in terms of energy expenditures and catalyst depletion. By first contacting the whole crude oil feedstock with an adsorbent for the sulfur-containing compounds, the adsorption effluent having a relatively lower sulfur content can be collected and provided to refiners without further treatment. The adsorbates, including adsorbed organosulfur compounds, are solvent desorbed resulting in a stream containing high levels of organosulfur compounds and a solvent. Following recovery of the solvent, the volume of the sulfur-containing feedstream that remains to be desulfurized in the hydroprocessing zone is substantially less than the original amount of whole crude oil feedstock.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 13/090,584 filed on Apr. 20, 2011, which is relatedto and claims the benefit of U.S. Provisional Patent Application Ser.No. 61/325,898 filed on Apr. 20, 2010, which are incorporated byreference herein in their entireties.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to improvements in whole crude oil processing,and in particular to an improved method for the desulfurization of wholecrude oil.

Description of Related Art

Natural petroleum and crude oil deposits are found worldwide over landand sea, having been created based on significantly different ecologicaland geological conditions since the time before fossil records on Earth.It follows that the compositions and constituents of extracted crude oilis different, and in some cases vastly different. However, virtually allcrude oils contain some level of sulfur compounds, includinginorganically combined sulfur and organically combined sulfur, i.e.,organosulfur compounds. Whole crude oil that contains a relatively lowlevel of sulfur compounds is commonly referred to as “sweet.” Often,recovered whole crude oil contains a substantial level of sulfurcompounds, such as hydrogen sulfide, sulfur dioxide, and organosulfiircompounds such as mercaptans, organic sulfides, organic sulfoxides,organic sulfones, thiophenes, benzothiophenes, and dibenzothiophenes,which are commonly referred to as “sour.”

Crude oil is generally converted in refineries by distillation, followedby cracking and/or hydroconversion processes, to produce various fuels,lubricating oil products, chemicals, and chemical feedstocks. Fuels fortransportation are generally produced by processing and blendingdistilled fractions from crude oil to meet the particular productspecifications. Conventionally, distilled fractions are subject tovarious hydrocarbon desulfurization processes to make sulfur-containinghydrocarbons more marketable, attractive to customers andenvironmentally acceptable.

The discharge into the atmosphere of sulfur compounds during processingand end-use of the petroleum products derived from sulfur-containingsour crude oil pose health and environmental problems. The stringentreduced-sulfur specifications applicable to transportation and otherfuel products have impacted the refining industry, and it is necessaryfor refiners to make capital investments to greatly reduce the sulfurcontent in gas oils to 10 parts per million by weight (ppmw) or less. Inthe industrialized nations such as the United States, Japan and thecountries of the European Union, refineries for transportation fuel havealready been required to produce environmentally clean transportationfuels. For instance, in 2007 the United States Environmental ProtectionAgency required the sulfur content of highway diesel fuel to be reduced97%, from 500 ppmw (low sulfur diesel) to 15 ppmw (ultra-low sulfurdiesel). The European Union has enacted even more stringent standards,requiring diesel and gasoline fuels sold in 2009 to contain less than 10ppmw of sulfur. Other countries are following in the footsteps of theUnited States and the European Union and are moving forward withregulations that will require refineries to produce transportation fuelswith an ultra-low sulfur level.

Furthermore, the price differential between sour crude oil and sweetcrude oil is increasing in favor of sweet crude oil. Hydrocarbondesulfurization processes are required to reduce the sulfur content.However, most desulfurization processing occurs after varying levels ofrefining of the crude oil. Therefore sour crude oil is sold at a lowerprice because the purchaser must undertake the expense ofdesulfurization.

The most common hydrocarbon desulfurization process is hydrotreating, orhydrodesulfurization. In typical hydrotreating processes, hydrogen and aspecific distilled hydrocarbon fraction are introduced to a fixed bedreactor that is packed with a hydrodesulfurization catalyst, commonlyunder elevated operating conditions, which can vary depending on thespecific fraction, type and ratio of catalyst, requisite degree ofdesulfurization, and other factors known to those of ordinary skill inthe art. Notably, the temperature and pressure conditions must befurther elevated to achieve the low and ultra low sulfur contentrequirements. However, these operational and capital costs for theseelevated conditions are higher, and these elevated conditions oftenpromote conversion of the feed into less desirable intermediates.

Most known advances in the industry for minimizing these undesirableeffects include development of more robust hydrotreating catalysts andadvanced hydrodesulfurization reactor designs. Alternative processeshave also been developed to meet the requirements of decreased sulfurlevels in fuels and other petrochemical products.

Conventionally, most oil refineries remove sulfur compounds after thewhole crude oil has been fractionated. For example, U.S. Pat. Nos.6,683,024, 6,864,215, 6,869,522, 6,930,074, 6,955,752 and 7,105,140, andPatent Publication US2001/002931 describe sorbent compositions that areused to desulfurize cracked-gasoline and diesel fuel. U.S. Pat. Nos.7,0743,24 and 7,291,259 disclose desulfurization of cracked-gasoline anddiesel fuel and other refinery fractions. Patent PublicationUS2005/0075528 describes the use of spent hydrotreating catalyst asadsorbent to treat specific fractions, including gasoline, gas oil,kerosene, or an atmospheric distillation residue.

Other processes are described in which adsorption techniques are used toremove hydrogenatable hydrocarbons, primarily in the context ofhalogenated hydrocarbons. For instance, U.S. Pat. Nos. 4,952,746 and4,747,937 generally disclose recovering compounds that can be chemicallymodified by addition hydrogen. Hydrogentable compounds are adsorbed, andthen hydrogenated in a hydrotreating reaction zone. Spent adsorbent isregenerated with an elution solvent, and the combined stream includingsolvent is processed in a hydrotreating zone. However, such a systemonly marginally reduces the flow requirements for a hydrotreating zone,since the elution solvent is hydrotreated along with the hydrogenatablecompounds. In addition, there is no teaching in U.S. Pat. Nos. 4,952,746and 4,747,937 of treating whole crude oil to remove organosulfurcompounds.

Patent Publication US2005/0205470 discloses a process for selectivelyremoving sulfur from feedstocks such as FCC cracked naphtha, jet fuel ordiesel using adsorption. Traditional hydrotreating is suitable for oilfractions, but not for whole crude. However, this is not suitable fortreating whole crude oil, as adsorption alone will result in asubstantial loss in the overall crude oil volume.

Importantly, none of the above-described references that incorporateadsorption disclose processes that are capable of desulfurizing wholecrude oil, prior to refining into its constituent products. As a result,the previously proposed and currently practiced methodologies requirerelatively greater complexity downstream in operations, due to the needto remove larger amounts of sulfur from naphtha, diesel fuel and otherrefinery products. In addition, according to the process of theabove-described references in which adsorbent materials are used totreat various fractions, no economic benefit is realized at the level ofproviding whole crude oil to refineries, e.g., directly from thepipeline or the tanker. Furthermore, none of the processes and systemsdescribed above reduces the requisite capacity of a hydroprocessingunit, typically an operation where substantial processing costs aredirectly proportional to the overall volume of crude oil that isprocessed in a given period of time.

It is therefore an object of this invention to provide a whole crude oildesulfurization process that can reduce the sulfur content whileminimizing the required capacity of a hydroprocessing reactor.

It is another object of the invention to balance the expense of wholecrude oil desulfurization with the price gain of the product deliveredto refiners.

As used herein, the term “whole crude oil” is to be understood to mean amixture of petroleum liquids and gases, including impurities such assulfur, as distinguished from refined fractions of hydrocarbons.

As used herein, the term “hydroprocessing” is to be understood toinclude hydrodesulfurization, hydrocracking, hydrodenitrification,hydrodealkylation and hydrotreating.

SUMMARY OF THE INVENTION

A primary objective of whole crude oil desulfurization is to convertsour grades of crude oil to more marketable and valuable products forrefinery operators. The present invention is directed to a whole crudeoil desulfurization system and process that included a combination of anadsorption zone and a hydroprocessing zone. This combined process andsystem reduces the requisite throughput for the hydroprocessing unit,conventionally a very costly process to operate both in terms of energyexpenditures and catalyst depletion.

By first treating the whole crude oil feedstock in the adsorption zone,the adsorption effluent can be collected and provided to refinerswithout further treatment, and the adsorbates, which include adsorbedorganosulfur compounds, are desorbed resulting in a stream containinghigh levels of organosulfur compounds and a solvent. The solvent isselected such that a major proportion thereof can be convenientlyseparated and recovered, for instance, by distillation. Accordingly, thevolume of liquid feed to be desulfurized in the hydroprocessing zone issubstantially less than the original volume of whole crude oilfeedstock. This is highly desirable, since a substantial cost ofoperating a hydroprocessing unit is proportional to the feed volume andnot highly sensitive to the sulfur content. Since the cost of anadsorption unit is typically much less than the cost of ahydroprocessing unit, such as a hydrodesulfurization unit,technologically mature units can be operated with desirable cost savingsusing the novel process and system of the present invention.

In a preferred embodiment, the process of the present invention isoperated upstream of the crude distillation unit in a typical crudeprocessing operation. It can be operated, for instance, downstream ofthe wellhead, before or after the Gas-Oil Separation Plant, upstream ofthe refinery limits, or within the refinery limits prior to the crudedistillation unit.

In the system and process of the present invention, a whole crude oilfeedstock is contacted with an adsorbent, typically in an adsorbent bed,on which sulfur-containing compounds are selectively adsorbed. Thedischarge is generally in the range of about 70% to about 99% of thetotal volume of the initial feedstock, in which the lower end of therange is applicable to feedstocks containing higher levels ofsulfur-containing compounds. The adsorbent is then desorbed with asolvent to extract the adsorbates and regenerate the bed.

In a preferred embodiment of the present invention, at least twoparallel adsorbent beds are used to operate continuously, so that whileone adsorbent bed is adsorbing the sulfur-containing compounds from thewhole crude oil feedstock, referred to herein as an “adsorption cycle,”the other adsorbent bed is regenerated, referred to herein as a“desorption cycle.”

Solvent is recovered and recycled from the mixture of solvent andsulfur-containing adsorbates. The separated hydrocarbon streamcontaining a relatively higher level of organosulfur compounds is fed toa hydroprocessing unit for desulfurization to produce a low sulfurcontent effluent. The low sulfur content effluent recovered from thehydroprocessing zone can be recombined with the low sulfur contenteffluent from the adsorption cycle, or sent to a separate processingpool.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofpreferred embodiments of the invention will be better understood whenread in conjunction with the appended drawings. For the purpose ofillustrating the invention, there are shown in the drawings embodimentswhich are presently preferred. It should be understood, however, thatthe invention is not limited to the precise arrangements andinstrumentalities shown. In the drawings the same numeral is used torefer to the same or similar elements, in which:

FIG. 1 is a schematic diagram of one embodiment of an improved wholecrude oil desulfurization system in accordance with the invention;

FIG. 2 is a schematic diagram of another embodiment of an improved wholecrude oil desulfurization system in accordance with the invention; and

FIG. 3 is a schematic diagram of a further embodiment of an improvedwhole crude oil desulfurization system in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

A process for treating whole crude oil containing organosulfur compoundsis generally described with respect to FIG. 1. A system 10 includes anadsorption zone 14 and a hydroprocessing zone 20. The process includescontacting a whole crude oil feed stream 12 containing organosulfurcompounds with a solid adsorbent material in the adsorption zone 14,wherein organosulfur compounds are adsorbed by the adsorbent material. Atreated effluent stream 16 having a reduced organosulfur compoundcontent is recovered from the adsorption zone 14.

When the adsorbent material has reached a predetermined percentage ofits adsorption capacity, organosulfur compounds are desorbed from theadsorbent material, e.g., by contacting the adsorbent material with asolvent for the organosulfur compounds. An increased organosulfurcompound purge stream 18 is recovered. The increased organosulfurcompound purge stream 18 is then desulfitrized in the hydroprocessingzone 20, from which a reduced organosulfur compound hydroprocessedstream 22 is recovered. Accordingly, the treated effluent stream 16having a reduced organosulfur compound content (as compared to the wholecrude oil feed stream 12) bypasses the hydroprocessing zone 20. Incertain embodiments, the reduced organosulfir compound hydroprocessedstream 22 and the treated effluent stream 16 recovered from theadsorption zone 14 can be collected in a common location 24 or stream 24(e.g., reservoir, tanker, pipeline, refinery crude feed stream).Alternatively, (not shown), the hydroprocessed stream 22 and the treatedeffluent stream 16 are collected or transported separately.

The sequence of hydroprocessing after adsorption allows the use ofcommercial hydroprocessing plant reactors and equipment such ashydrotreating units and provides a significant economic advantage. Thecost of building and operating a hydroprocessing unit is generallyproportional to the feed volume, and is generally not sensitive to thesulfur content up to about 6 wt %. Therefore, since the cost ofadsorption, desorption and other unit operations equipment is generallymuch less than the cost of hydroprocessing equipment such ashydrotreating units, the same amount of whole crude oil can bedesulfurized at a reduced cost using relatively smaller hydrotreatingunits downstream of the adsorption unit(s), as compared to using only arelatively larger hydrotreating unit to achieve the same or similarlevel of desulfurization of a give whole crude oil feedstream.

The adsorbent zone 14 can include any type of adsorbent bed or otherstructure and associated systems for containing adsorbent material. Incertain embodiments, the adsorbent material is contained in at least onefixed bed. The adsorbent zone 14 can also be a plurality of fixed bedsin parallel, series, or a combination including parallel and series; oneor more agitated or non-agitated slurry vessels; or one or more movingbed adsorbers. The whole crude oil feed 12 can be treated in batch,semi-continuous or continuous operation, depending on the type andnumber of adsorbing units in the adsorption zone 14.

The adsorbent material is characterized by a high capacity and highselectivity for the sulfur compounds that are present in whole crudeoils. In general, the adsorbent material has an adsorbent capacitysuitable to remove at least about 5 to about 53 weight percent of theorganosulfur compounds contained in the original whole crude oil feedstream 12. In certain preferred embodiments, the adsorbent material hasan adsorbent capacity suitable to remove at least about 30 weightpercent, and in certain embodiments higher levels, of the organosulfurcompounds contained in the whole crude oil feed stream 12.

In addition, a suitable adsorbent material can be readily regeneratedfor repeated use if the adsorption unit. For instance, suitableadsorbent material can be used for at least about 50 cycles, preferablyat least about 200 cycles of adsorption and desorption.

Further, the adsorbent material preferably does not react with sulfurgases that can be present in the whole crude oil stream 12, such ashydrogen sulfide gas. Accordingly, unlike other prior art processes thatuse beds of catalytic to remove hydrogen sulfide, generally byoxidation, organosulfur compounds are adsorbed in a manner that utilizesthe “purge” stream to recover whole crude oil, in a purge stream 18having increased levels of organosulfur compounds.

The adsorbent material/materials can include materials such as zincoxide. manganese oxide, metals over high surface area supports likesilica, alumina, zeolites, activated carbon, mesoporous silica molecularsieves (e.g., Al-MCM-41), and bauxite. Particularly suitable adsorbentsthat have been identified as having suitable adsorbent capacity foradsorbing organosulfur compounds from whole crude oil streams includealumino silicates such as type Y zeolite (metal promoted, ion-exchangedand other forms) and activated carbon powders. In certain embodiments, acombination comprising at least one of the above mentioned adsorbentmaterials can be used. For instance, these different adsorbent materialscan be admixed, or in staged sections or adsorbent beds (in the case ofseries adsorbent beds).

The adsorbent preferably includes properties such as pore size thatpermits the large organosulfur compounds access to the internaladsorption sites. For instance, in a preferred embodiment, adsorbentmaterial is selected that has an average pore diameter of about 10 toabout 50 nanometers, a surface area of about 100 to about 500 squaremeters per gram, a pore volume of about 0.5 to about 0.8 cubiccentimeters per gram, and a bulk density of about 0.55 to about 0.75grams per cubic centimeter. In addition, preferred adsorbent particlesare extrudates having a diameter of about 1 to about 5 millimeters and alength of about 0.5 to about 2.5 centimeters.

In preferred embodiments, large pressure drops (e.g., greater than about0.25 bar/meter) are avoided by selection of suitable adsorbent material(including selection of suitable particle size), and suitable operatingconditions such as temperature, pressure and space flow velocity.Operating conditions during adsorption can include: a temperature ofambient to about 70° C., and in certain embodiments ambient to about 50°C.; a pressure of ambient to about 5 bars, and in certain embodimentsambient to about 3 bars; and a liquid hourly space velocity of about0.5/hour to about 10/hour, and in certain embodiments about 1.0/hour toabout 8.0/hour.

The organosulfur compounds from the whole crude oil stream can includemercaptans, organic sulfides, organic sulfoxides, organic sulfones,thiophenes, multi-ring thiophenes, benzothiophenes, dibenzothiophenesand other sulfur-containing organic compounds, and combinationscomprising at least one of the foregoing organosulfur compounds. Duringhydroprocessing, the amount of organosulfilr compounds in the purgestream 18 having increased levels of organosulfur compounds areconverted to the reduced organosulfur compound hydroprocessed stream 22.

In certain embodiments, sulfurous gases (such as hydrogen sulfide gas)can be removed from the treated effluent 16 with a fractionation processto further reduce the overall sulfur content, as in known to those ofordinary skill in the in the art of hydrotreating. The elemental sulfurcan be recovered for commercial sale.

Referring now to FIG. 2, an embodiment of a process and system fordesulfurizing whole crude oil (more generally shown with respect toFIG. 1) is shown. A whole crude oil desulfurizing system 110 generallyincludes at least two parallel adsorption units 34, 54 in an adsorptionzone 114. During the adsorption cycle, in which one adsorption unit 54is adsorbing organosulfur compounds from the whole crude oil stream 32,the other adsorption unit 34 is in the desorption cycle, where it isdesorbing the previously adsorbed organosulfur compounds into anincreased organosulfur compound purge stream 38.

During an adsorption cycle of the adsorption unit 34, a treated effluentstream 36 having a reduced organosulfur compound content is recoveredfrom the adsorption unit 34. Likewise, during an adsorption cycle of theadsorption unit 54, a treated effluent stream 56 having a reducedorganosulfur compound content is recovered from the adsorption unit 54.The treated effluent streams 36, 56 can be directed, for instance, intoa treated effluent stream 116.

During a desorption cycle, shown with respect to the adsorption unit 34in FIG. 2, the adsorbates (including organosulfur compounds adsorbed tothe adsorbent material) are desorbed to remove the increasedorganosulfur compound purge stream 38. A desorption cycle is alsocarried out in the adsorption unit 54 (not shown). The desorption cyclecan commence, for instance, when the adsorbent material in theadsorption unit 34 or 54 has reached a predetermined percentage of itsadsorbent capacity. In certain embodiments, the whole crude oils stream32 is adsorbed until the level of organosulfur compounds has beenreduced by a predetermined percentage. The amount of sulfur reductioncan be monitored in the treated effluent stream 36, by various processesincluding but not limited to X-ray florescence.

A semi-continuous operation can be established by adsorbing in theadsorption unit 54 during the desorption cycle of adsorption unit 34,where the whole crude oil stream 32 is directed to the adsorption unit54 for adsorptive desulfurization. The process can cycle betweendesorption and adsorption as needed.

The adsorption bed 34 can be regenerated by various methods.Furthermore, upon regeneration of the adsorbent material, at least about95%, preferably at least about 99%, of the adsorbate is removed.

In the schematic diagram of FIG. 2, the desorption cycle employs astripping solvent. The stripping solvent used in the process of thepresent invention is characterized by the following properties:

-   -   a. the ability to dissolve sulfur organic compounds;    -   b. it is in a liquid phase or supercritical state at the        stripping conditions; and    -   c. sufficiently volatile for reuse after separation of sulfur        compounds.        In addition, economic considerations are important. Examples of        suitable stripping solvents include toluene, hexane, butane,        pentane, or combinations comprising at least one of the        foregoing solvents. In certain embodiments, toluene is a        desirable stripping solvent as it is an inexpensive aromatic        solvent, thereby increasing the solubility of a greater portion        of aromatic organosulfur compounds. Hexane, pentane and butane        will dissolve a smaller portion of the aromatic sulfur        compounds, especially those with multiple aromatic rings and        nitrogen heteroatoms, in addition to sulfur, but energy savings        in recovering the solvent are realized.

The adsorbent in the adsorption unit 34 is contacted with a strippingsolvent in a desorbing stream 128. The purge stream 38 from thedesorption cycle therefore includes organosulfur compounds and strippingsolvent. All or a substantial portion of the stripping solvent used inthe purge stream 38 is recovered, for instance, in a distillation unit126.

The effluent from the distillation unit 126, a hydrocarbon stream 118having an increased level of organosulfur compounds, is then processedin the hydroprocessing zone 120 for desulfurization. A hydroprocessedstream 122 having a reduced level of organosulfur compounds isrecovered.

In certain embodiments, the hydroprocessed stream 122 and the treatedeffluent stream 116 recovered from the adsorption zone 114 can becollected in a common location 124 or stream 124. Alternatively, (notshown), the hydroprocessed stream 122 and the treated effluent stream116 are collected or transported separately.

Operating conditions during desorption, for instance using toluene as astripping solvent, can include: a temperature of ambient to about 70°C., and in certain embodiments ambient to about 50° C.; a pressure ofambient to about 5 bars, and in certain embodiments ambient to about 3bars; and a liquid hourly space velocity of about 0.5/hour to about10/hour, and in certain embodiments about 1.0/hour to about 8.0/hour.

The operating conditions for adsorption and desorption can be similar,realizing process economics and configuration advantages related toheating or cooling the bed. Since typical stripping solvents haverelatively low viscosity levels, there is a lower pressure drop acrossthe bed, or a higher velocity at the same pressure drop. For butane andlighter hydrocarbons, stripping can be accomplished in a liquid phase orsupercritical state, and the pressure and temperature conditions shouldbe set accordingly, i.e., such that the fluid is in its liquid statewith the temperature below the solvent's critical temperature and thepressure above the solvent's vapor pressure, and such that the fluid isin the supercritical state with the temperature slightly above thesolvent's critical temperature point and the pressure around thesolvent's critical pressure.

In a further embodiment of a process and system for desulfurizing wholecrude oil, and referring now to FIG. 3, a system 210 is shown similar tosystem 110 described with respect to FIG. 2, with the use of compressedgas or supercritical solvent. For instance, system 210 can use as astripping agent one or more of supercritical carbon dioxide,supercritical ethane, supercritical ethylene, supercritical propane andsupercritical butane.

During a desorption cycle, shown with respect to the adsorption unit 34in FIG. 3, the adsorbates (including organosulfur compounds adsorbed tothe adsorbent material) are desorbed to remove purge stream 38 having anincreased level of organosulfur compounds. A desorption cycle is alsocarried out in the adsorption unit 54 (not shown). The desorption cyclecan commence, for instance, when the adsorbent material in theadsorption unit 34 or 54 has reached a predetermined percentage of itsadsorbent capacity. In certain embodiments, the whole crude oils stream32 is adsorbed until the level of organosulfur compounds has beenreduced by a predetermined percentage, for instance, ranging from about5 to 53 weight percent, preferably about 30 to 53 percent.

A solvent desorbing stream 228 is passed through the adsorption unit 34.The purge stream 38 from the desorption cycle therefore includesdesorbed adsorbate, i.e., organosulfur compounds, and solvent. At leasta portion, and preferably, substantially all, of the solvent used in thedesorption cycle purge stream 38 is recovered, for instance, in aseparation unit 226, such as a distillation unit. The solvent isrecompressed in a compressor 230, for instance, during continueddesorption in a desorption cycle, or when needed in a subsequentdesperation cycle. The increased organosulfur compound whole crude oilstream 118 can then be processed in the hydroprocessing zone 120 fordesulfurization, and a hydroprocessed stream 122 having a reduced levelof organosulfur compounds is recovered, as discussed above.

Operating conditions during desorption, for instance using supercriticalcarbon dioxide as a stripping solvent, can include a temperature ofgenerally about 31° C. to about 70° C. and a pressure of about 72 toabout 1000 bars with a liquid hourly space velocity of about 0.5/hour toabout 20/hour. In preferred embodiments, operating conditions duringadsorption can include a temperature of generally about 31° ° C. toabout 70° C. and a pressure of about 72 bars to about 200 bars with aliquid hourly space velocity of about 1.0/hour to about 0/hour.

In the processes described herein, unlike conventional desulfurizationprocesses, gaseous sulfur components of the whole crude oil stream (suchas hydrogen sulfide) are not the targets of the adsorption process.Rather, organosulfur compounds, mercaptans, organic sulfides, organicsulfoxides, organic sulfones, thiophenes, benzothiophenes, multi-ringthiophenes such as dibenzothiophenes, and other sulfur-containingorganic compounds are the desired adsorbates, and hydrogen sulfide issubstantially not adsorbed. Thus, the reduced organosulfur compoundadsorbent effluent stream is discharged having substantially the sameamount of hydrogen sulfide gas as the whole crude oil stream. Thistreated effluent stream can be further subjected to a fractionationprocess to remove the gas phase containing hydrogen sulfide gas prior todelivery, storage or combination with the hydrotreated desultfurizedstream described herein.

EXAMPLES

The following examples illustrate specific embodiments of the method(s)of this invention. The scope of this invention is not to be consideredas limited by the specific embodiments described therein, but rather asdefined by the claims.

Example 1

In this example, 3 grams of type Y zeolite powder was activated in avacuum oven at 175° C. and a gauge pressure of 14 psig overnight. The Yzeolite powder was then cooled to room temperature and placed in a 100ml wide-mouth bottle, to which 15 grams of crude oil having a totalsulfur content of 3.01 wt % was added. The mixture was mechanicallyshaken for 8 hours to reach adsorption equilibrium. After the shakingwas stopped, the zeolite powder was allowed to settle by gravity and theupper liquid layer was analyzed for total remaining sulfur which wasfound to be 1.4 wt %. The liquid was then decanted from the bottle andthe remaining solid was washed with 30 grams of toluene. Analysis byX-ray fluoresce indicates that the toluene removed 67% of the totalsulfur from the adsorbent.

Example 2

Example 1 was repeated, except that Ni—Y zeolite powder (prepared by ionexchange) was employed as the adsorbent. The remaining total sulfur inthe liquid was 1.2 wt % and toluene removed 54 wt % of the total sulfurfrom the adsorbent.

Example 3

Example 1 was repeated, except that 1-Y zeolite pellets were employed asthe adsorbent. The remaining total sulfur in the liquid was 2.87 wt %and toluene removed almost 100 wt % of the total sulfur from theadsorbent.

Example 4

Example 1 was repeated, except that activated carbon powder was employedas the adsorbent. The remaining total sulfur in the liquid was 2.61 wt %and toluene removed 100 wt % of the total sulfur from the adsorbent.

The process of the invention has been described and explained withreference to the schematic process drawings and examples. Additionalvariations and modifications will be apparent to those of ordinary skillin the art based on the above description and the scope of the inventionis to be determined by the claims that follow.

What is claimed is:
 1. A process for treating whole crude oil containingorganosulfur compounds comprising: a. contacting, upstream of a crudedistillation unit, a whole crude oil feed stream containing organosulfurcompounds with a solid porous adsorbent material having average porediameter in the mesoporous range to about 50 nanometers, whereinorganosulfur compounds are adsorbed by the adsorbent material; b.recovering a treated effluent stream having a reduced level oforganosulfur compounds; c. desorbing at least a portion of theorganosulfur compounds from the adsorbent material, and recovering apurge stream having an increased level of organosulfur compounds fromthe adsorbent material; and d. hydroprocessing the purge stream andrecovering a hydroprocessed stream having a reduced level oforganosulfur compounds.
 2. The process as in claim 1, wherein theadsorbent material is contained in at least one fixed bed.
 3. Theprocess of claim 1, wherein the hydroprocessed stream is combined withthe treated effluent stream.
 4. The process of claim 1, wherein thetreated effluent stream is further subjected to a fractionation processto remove a gas phase that contains at least hydrogen sulfide gas. 5.The process of claim 1, wherein the treated effluent stream contains atleast about 5 to 53 weight percent less organosulfur compounds than thewhole crude oil stream.
 6. The process of claim 1, wherein the treatedeffluent stream contains at least about 30 to 53 weight percent lessorganosulfur compounds than the whole crude oil stream.
 7. The processof claim 1, wherein the desorbing step employs a stripping solvent. 8.The process of claim 7, wherein the purge stream contains at least aportion of the stripping solvent, and organosulfur compounds, andwherein at least a portion of the stripping solvent in the desorbedpurge stream is distilled and recycled.
 9. The process of claim 7,wherein the stripping solvent comprises a solvent selected from thegroup consisting of toluene, hexane, butane, pentane and combinationscomprising at least one of the foregoing solvents.
 10. The process ofclaim 7, wherein the stripping solvent comprises toluene.
 11. Theprocess of claim 1, wherein the desorbing step employs a supercriticalfluid.
 12. The process of claim 11, further comprising recovering thedesorbed purge stream containing at least a portion of the supercriticalfluid and the increased organosulfur compound purge stream, and whereinat least a portion of the supercritical fluid in the desorbed purgestream is compressed and reused as the stripping solvent.
 13. Theprocess of claim 11, wherein the supercritical fluid comprises asupercritical fluid selected from the group consisting of supercriticalcarbon dioxide, ethane, supercritical ethylene, supercritical propane,supercritical butane and combinations comprising at least one of theforegoing supercritical fluids.
 14. The process of claim 11, wherein thesupercritical fluid comprises supercritical carbon dioxide.
 15. Theprocess of claim 1, wherein the adsorbent material has an adsorbentcapacity, and wherein contacting comprises: passing the whole crude oilfeed stream through a first adsorbing bed containing adsorbent materialuntil the adsorbent material in the first adsorbing bed has reached apredetermined percentage of its adsorbent capacity; and passing thewhole crude oil feed stream through a second adsorbing bed containingadsorbent material when the adsorbent material in the first adsorbingbed has reached the predetermined percentage of its adsorbent capacity.16. The process of claim 15, further comprising desorbing the firstadsorbing bed while the whole crude oil feed stream is passed throughthe second adsorbing bed.
 17. The process of claim 15, wherein thepredetermined percentage is greater than at least 95%.
 18. The processof claim 1, wherein the adsorbent material is selective to organosulfurcompounds including benzothiophenes dibenzothiophenes, other multi-ringthiophenes, and combinations comprising at least one of the foregoingorganosulfur compounds.
 19. The process of claim 1, wherein theadsorbent material is selected from the group of materials consisting ofY-zeolites, active carbon powders and a combination comprising at leastone of the foregoing materials.
 20. The process of claim 1, whereinhydroprocessing is selected from the group consisting ofhydrodesulfurization, hydrocracking, hydrodenitrification,hydrodealkylation and hydrotreating.